Belt tightener and guide



y 31, 1932. .1. RED

BELT TIGHTENER AND GUIDE Filed Dec. 27, 1929 5 Sheets-Sheet 1 J. REID 1,861,133

BELT TIGHTENER AND GUIDE May 31, 1932.

5 Sheets-Sheet 2 Filed Dec. 27, 1929 3mm Jab: fleid 1 May 31,1932. w lD 1,861,133

BELT TIGHTENER AND GUIDE Filed Dec. 27, 1929 5 Sheets-Sheet 3 36 f as Zlwuenioo m I 1/0/22: fieid Patented. May 31,1932

' JOHEREID, or. on; CITY; PEnNsYLvANIA VIBELT-ITIGHTENER, AND GUIDE;

7 Application mednee mber'z'z, {1929; Serie1Nb. 41 G,973.-

This invention" relates to a belt tightenerparticularly for use on a bandwheel power belt. Thedevice isde'signedfcr use on :powers- Wliich drive eccentrics to which devices for driving the-p umps of ;0il wells are attached.

It'has been the practice foranumber of years to use-manual helt'tightenerspr idle'rs on such belts! The travelqf. these' idlers has been fron'rthree to ten feet; In normal use" ene eccentric usuallyhas more Wells tod'rive than another,- which causes an alternate slackening and tightening" of the belt. When" end; less belts were used; it became desirable h to provide: automatic: means for" compensating for this 'peri-odicchfange' inelack: and yet" al 10w the" full travel" of the idler. This 1 has been-iac'cor'nplisheddn the past by systems 0f" weights and pulleys; These devices intro ducedseveral difficulties. When the-rbelt I flbpped, the idler would rehoundaand travel" back the far. When it" wasreturned under; the acti on of the" weights; the" idler would" strike the belt a" severe blow which would 7 usually place" ai'pr'e'ss'ure" onithe belt beyond the"safe"working" stress: the belt" broke, the weightsiw-ould drag thewidler the full length of its travel at arapid rate whlch would p'ut a severe: strain on'thefdeviceand endanger w'orkinen in the vicinity:

An object of "my invention is to provide a belt tightener which'shall automatically'- take-up normal variatidnsin slack and which:

shall be able to' be adji stjed'ifcr "theusual full" length" of travel;

ti ghtener that] shall fnotovertrav'el' upon sud den increa'sesin, belt "tension such as those dneltdfloppingpftheibelti a c A fiirther lob j ectlis to. limit lthe travel 0fe v e un vbmak ge i t V A ful-then objectkisfto provide .meansfori a c selectively renderingytheautomatic takeupoperative on inoperative. V c

Other objects I be apparent -to' those;

skilledlin the art; fnomathe fdllowingrdescrip-d 5 Fig: '1" is a planzaview of s' one' illustrative A further object" isi-te' provide su'chs'a' belt I form of my'device in operative relationship with the'dr'iving belt of apower,

F 1g; 2is a= plan v-iewof the'beltjtiglitenei assembly, I

Fig.'-3 is an elevation of the device'sh-own' in Fig; 2, l I

Fig.4 is a horizontalsection oftheautb I matic take up device,' n

r Fig. Sisasectiontzken along'line 5 -5 0f Fig. k showing themeans-ferrendering tlie' take up device'operative or inoperative;-

Fig 6 is-a section taken along-lineG-G of Fig;- 4, and

F ig: 7 is a'sectio'n similar to that shown in Fig Gibut which shows an alternative constrnction of the means therein shown.

The'p'umping power leis of theb'anclwheeltypeand is driven-by the endless -helt 2 'frbm the primemover 3, which may be an'internal comhustion" engine. The eccentrics 4" are driven by the power 1 and to'said eccentrics are attachedthe" driving elements (notsh0wn)- for varionspumping devices.- The belt tightener-5-is placed against-the slack sid'e-ofthe belt 2; preferably with its direction of travel "parallel to' the tight side'6' of thebelt: Tliebel't tightener 5' includes aframe 7." This" frame is made cf'twov ship channels 8 which are held rigid and in"aline1nent by' crossbraces 9 and 10 one at eachend of sa'id frame; 'The' frame is-se-curelyboltedto'the foundation 1-1 by bolts 125' Thisdounda tion preferably consists of concrete blccks fi rmly set'in the floor'a-t, the desiredlocation-r 5 The idler mechanism includes a-carriage 13 carrying the idlerpulley M. The pulley 14 is carried by a shaft 15 which in' turn is mounted on the device .16 which is securely" fastened -to the carriage 13 atl? but which is angularly adjust-able: with respect'to tlie carriage by the two set screws; 18"and*19. Jamnutsf'20 prevent screws 18 and jl9 ircmi turi'ling' after an adj ustment. has been 'n'1ade'." The-entire carriage 13*is adapted to Irinve" along theflt eps of the" channels 8" on the "roll ers 21 The carriage 1 3 is moved alon'g theframeby'means o'fthe" feedsh'aft 22,-1which is 1 c provided- With-threads '22" which enga-ge. v threadson "thecarria'ge 13 21.613 (Dhe end 10 Member 9 is also provided withtwo walls 28- and 29 forming a transverse chamber 30 between them. The walls 28 and 29 have openings 31 and 32 respectively in them, through which the feed shaft 22 passes freely. A collar 33 is made to fit snugly into the interior of the tubular member 26, and has a recess 34 for the reception of a spring 35. Collar 33 passes freely over the end of shaft 22, and

iskept from slipping off by the nut 36 threaded onto the end of said shaft. It can be seen that sprin is confined between the shoulder 27 an the collar 33. I

Shaft 37 is journaled at opposite ends in brace 10 and wall 29 of brace 9 at 38 and 39 res ctivel A crank 40 is provided on one en of sai shaft to actuate it. A collar 41 is securely fastened to shaft 37. Arm 42 is formed integral with said collar. A link 43 is pivotally connected at 44 to arm 42 and at '45 to projection 46, forming part of the actuating member 47. Member 47 carries two arcuate arms 48 which are concentric with and extend approximately half way around the shaft 22, but which allow said shaft to pass freely between said arms. In the outer end of each arm 48 is securely fastened a pin 49, passing through an arcuate slot 50 concentric with said shaft 22, said slots being provided in the wall 29. Two jaws 51 are fitted into the chamber 30, one on either side of member 22. Each of these aws 51 has arcuate slots 52 adapted to engage with the projecting rings 53 formed integral with feed shaft 22 when slides 51 are moved toward said feed screw 22. These rings extend for a short distance beyond each of the walls 28 and 29. The pins 49 engage with the slots 49" in the 'aws 51. These slots are eccentric with the axls of the feed shaft 22and the arms of 'the actuating device 47. Thus upon rotation of the device 47 in a clockwise direction in .Fig. 6,,the jaws 51 will move toward the feed screw 22, while upon rotation in a counter clockwise direction the jaws 51 will move away from feed screw22.

the belt. The set screws 18 and 19 may be changed if necessary to cause the belt to en-;

gage pulley 14 throughout the width of the belt. vThe spring 35 being under compres sion will, through its reaction upon collar 33, tend to move the carriage to the left as the device appears in Fig. 1. Thus if slack occurs in the belt 6, the spring 35 will cause the pulley to take up such slack. The spring 35 is so designed that it can be put under sufficient compression to take care of all ordinary slack. y

, If the belt should break, the spring 35 will merely expand to its fullest extent, which will cause thecarriage to move only a short distance beyond its previous position, no great shock being imparted to the mechanism.

;Upon the occurrence of a flopping of the belt,'thespring 35 will be placed under a constantly increasing compression, which will not only prevent the idler pulley from-overtraveling, but will also exert a snubbing action on the belt. Thus upon the return of the belt to its normal position the idler pulley, having closely followed the belt, will not exert any undue strains on the belt.

In some instances it may be desirable to render the automatic takeup device inoperative. In that case, the crank 40 is turned so asto operate the shaft 37 in a clockwise direction which, through the arm 42 and link' 43, will likewise turn the actuating member 47 in a clockwisedirection, moving the slots 52 intoengagement with the rings 53.. This will lock the feed screw 22 against longitudinal motion. However, the feed shaft 22 is free to turn and the carriage 13 may still be adjusted along the frame by means of the crank 25. It can be seenthatthis locking can occur whether the spring 35 is under compression or not. vThis is due to the fact that the rings 53 are provided over a distance at least equal to the maximum dist ance throu h which the screw 22 can move under them uence of the spring 35. Thus there will always be some rings with which the slots 52 can engage. By turning the shaft 37 in a counter clockwise direction, the jaws 51 will be retracted and the automatic take up device again rendered operative.

y In Fi 7, which shows an alternative locking device, 22 indicates the feed screw with the rings'cooperatingwith the slots 52 in the evers 54. Eachof the levers 54 is pivotedat 55 to the frame. A spring 56 biases the levers 54 so that the slots 52' normally are out of engagement with the feed screw 22, allowing ongitudinal' movement thereof as de: scribed in connection with the first modification. The shaft 37 carries a-.double cam 57, which'is placed between the endsof the levers on the side of the pivot :points 55 opposite the spring 56. The figure'illustrates the normal; position. 5 If the shaft 37 isturned in either direction from the position shown,.each of the cam faces willmove one of thelev'er arms against the action of the spring-56and fo heq' s 51'. i t a me t w t f h laws 51', which-are formed on the ends of the feed shaft 22. This looks feed shaft 22 against longitudinal movement as described in connect-ion with the other modification.

Various changes may be made in the illustrated form of my invention Within the scope of the appended claims.

Having described my invention, I claim 1. In a belt tightener, a guide frame, an idler pulley adapted to bear against the slack side of a driving belt, a feed screw for adjusting said pulley along said frame, spring means for pressing said pulley against said belt, and means for selectively rendering said spring means operative or inoperative.

2. In a belt tightener, a feed screw, an idler pulley carried by said feed :screw, a guide frame, a spring interposed between said guide i frame and said feed screw, a pair of movable jaws in said guide frame, cooperating rings and grooves on said feed screw and said movable jaws, and means for moving said jaws into or out of engagement with said feed screw. I

3. In a belt tightener, a feed screw, an idler pulley carried by said feed screw, a guide frame, a spring interposed between said guide frame and said feed screw, a pair of movable jaws in said guide frame, cooperating rings and grooves on said feed screw and'said movable jaws, and means formoving said jaws into or out of engagement with said feed screw, comprising a rotatable actuating member, pins carried by said member, slots in said jaws, said slots being eccentric to the axis of said actuating member, said pins being received in said slots, and means to selectively rotate said actuating means in one direction or the other. 1 I

4:. In a belt tightener, a feed screw, an 40 idler pulley carried by said feed screw, a guide frame, a spring interposed between i said guide frame andsaid feed screw, a pair of pivoted jaws in said. guide frame, cooperating rings and grooves on said feed screw and said pivoted jaws, and means for moving said jaws into or out, of engagement with said feed Screw, said means comprising a rotatable' actuating member. and a double cam mounted upon said member cooperating with said pivoted jaws.

The foregoing specification signed at Oil City, Penna., this 24th day of December, 1929.

JOHN REID. 

